POLYDOPAMINE AS A VERSATILE PLATFORM FOR CONJUGATION OF ANTIBACTERIAL ENZYMES FOR SURFACE TREATMENTS

The use of polydopamine (PDA) for the facile generation of nano-thick films with potent antibacterial and antibiofim properties are reported. Different surfaces coated with thin PDA films of about 20-30 nm were covalently immobilized with the antibacterial enzyme Lysostaphin (Lst) under physiological conditions that preserve the enzymatic activity of the enzyme to degrade bacterial membrane¹. Enzyme-linked immunosorbent assay (ELISA), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy XPS studies confirmed the attachment of the enzyme onto the surfaces, while Live/dead fluorescent and turbidity assays demonstrated that the surfaces are highly active against S. aureus. We also found that Lst-PDA films eradicate S. aureus biofilm and kill the bacteria in less than 15 min, without leaching from the surface. Similar approach was used for the successful conjugation of recombinant triple-acting fusion enzymes to PDA-coated surfaces and medical devices. These enzymes simultaneously target and cleave three different sites on bacterial membrane, making them highly refractory to resistance development. We also demonstrated that PDA coated surfaces conjugated with our enzyme constructs remain active against bacteria for extended periods and prevent biofilm formation. Finally, we show that immobilization of PDA surfaces with antibacterial enzyme constructs is more effective and robust when the protein contains a His-tag fragment, which is frequently used for the purification of recombinant proteins through Ni-column chromatography.

1. Yeroslavsky, G., Girshevitz O., Foster-Frey J., Donovan D. M. and Shai Rahimipour

Langmuir, 2015, 31 , 1064–1073